1 Chronicles 23:1

Here we have, I. The crown entailed, according to the divine appointment, Ch1 23:1. David made Solomon king, not to reign with him, or reign under him, but only to reign after him. This he did, 1. When he was old and full of days. He was but seventy years old when he died, and yet he was full of days, satur dierum - satisfied with living in this world. When he found himself going off, he made provision for the welfare of the kingdom after his decease, and pleased himself with the hopeful prospect of a happy settlement both in church and state. 2. He did it in parliament, in a solemn assembly of all the princes of Israel, which made Adonijah's attempt to break in upon Solomon's title and set it aside, notwithstanding this public recognition and establishment of it, the more impudent, impious, and ridiculous. Note, The settling or securing of the crown in the interests of the temple is a great blessing to the people and a great satisfaction to those who are themselves leaving the world. II. The Levites numbered, according to the rule in Moses's time, from thirty years old to fifty, Num 4:2, Num 4:3. Their number in Moses's time.

— Matthew Henry's Concise Commentary (public domain)